Evolution we can watch happening — NEET & JEE Questions

Question 1 · difficulty L1 · recall

Selection favouring both extremes over intermediates:

• A. genetic equilibrium
• B. disruptive selection
• C. directional selection
• D. stabilising selection

Question 2 · difficulty L1 · recall

Selection favouring intermediate phenotypes:

• A. disruptive selection
• B. sexual isolation only
• C. stabilising selection
• D. directional selection

Question 3 · difficulty L2 · understanding

Selection shifting the population mean toward one extreme:

• A. directional selection
• B. disruptive selection
• C. random mating
• D. stabilising selection

Question 4 · difficulty L2 · understanding

The rapid spread of antibiotic resistance in a bacterial population is an example of evolution because

• A. heritable variants differ in survival and reproduction under antibiotic selection
• B. individual bacteria deliberately mutate because they need resistance
• C. all bacteria become resistant without genetic change
• D. antibiotics stop natural selection

Question 5 · difficulty L2 · understanding

Industrial melanism in peppered moths is commonly used to illustrate

• A. natural selection changing phenotype frequencies when environmental conditions change
• B. inheritance of acquired soot colour during life
• C. absence of heritable variation
• D. random mating without selection

Question 6 · difficulty L3 · application

After repeated insecticide use, a pest population becomes dominated by resistant individuals. What is the best explanation?

• A. Resistant variants left more offspring under insecticide exposure
• B. The insecticide taught susceptible individuals to become resistant
• C. Every individual acquired the same heritable change at once
• D. Selection stopped after spraying

Question 7 · difficulty L3 · application

A drought leaves mostly large, hard seeds on an island. In following generations, average finch beak depth increases. Which process is most directly illustrated?

• A. Natural selection acting on heritable beak variation
• B. Use and disuse changing every beak identically
• C. No evolution because only morphology changed
• D. Artificial selection by humans

Question 8 · difficulty L3 · application

Which observation would provide the strongest evidence that a population has evolved over several generations?

• A. A heritable allele frequency changes from 0.2 to 0.7
• B. One individual grows larger after eating more food
• C. A leaf wilts during a hot afternoon
• D. An animal learns a new behaviour

Question 9 · difficulty L3 · application

A bacterial culture contains rare resistant cells before exposure to an antibiotic. After treatment, resistant cells become common. This supports the idea that

• A. selection acts on existing heritable variation
• B. the antibiotic necessarily creates resistance only after exposure
• C. all genetic variants have equal fitness under treatment
• D. resistance cannot evolve rapidly

Question 10 · difficulty L4 · application

Which experimental design best demonstrates evolution by natural selection?

• A. Track heritable trait frequencies across generations under a defined selective pressure and a control condition
• B. Measure one individual's heart rate before and after exercise
• C. Observe a single organism learning a task
• D. Compare two unrelated species without inheritance data